1. Field of the Invention
The present invention relates generally to the field of light fixtures and more specifically, to an apparatus for securing a lens to a light fixture housing in a relatively watertight seal.
2. Background of the Invention
Various light fixtures have been designed in the past for use in damp or wet environments which require sealing the fixture to protect the lamps and wiring inside the fixture. Usually such systems are relatively complex and are difficult to open and close when repairing the internal wiring or replacing the lamps or bulbs therein.
A number of fixtures have previously been designed which include various forms of latch mechanisms that allow release of the protective lens or some other portion of the fixture for access to its interior. For example, U.S. Pat. No. 5,865,532 discloses a light fixture with a device for securing a transparent screen or lens to the base of a light fixture. The lens is secured to the base by a plurality of separately operable flexible hook-shaped elements. Thus, the force holding the lens in place is applied at discrete points and an effective seal along the entire edge of the lens cannot be formed.
U.S. Pat. No. 3,654,453 discloses a latch mechanism that includes a movable member having an end which engages a catch element provided on the housing of a light fixture. The single latch mechanism holds a lens in place against the housing in one location and does not create a seal along the entire edge of the lens.
U.S. Pat. No. 1,729,892 discloses a lamp body and door fastening device which includes a clip arrangement that holds a lens in place with a substantially watertight seal. However, the clip is not easily operable without tools to remove the lens for bulb replacement.
U.S. Pat. No. 6,267,491 relates to a lens retention means for a vehicle""s lamp assembly in which the lens snaps into the housing. U.S. Pat. No. 5,172,976 discloses a light fixture that uses a pair of latch/hinge assemblies on one side of the lens and a pair of latch assemblies on the other side of the lens to secure the lens to the light fixture""s housing.
In addition to the above, there are known light fixtures that require that an end plate be removed to allow access for relamping the light fixture. These, and other known light fixtures, require that two or more fasteners be removed from the light fixture""s housing to relamp the light fixture. One problem with such fasteners is that after being removed, they become dislodged from the light fixture, i.e., they become loose and can fall from the work area onto pedestrians walking on the street below or into sewers, drains, etc. These light fixtures can become especially cumbersome to use when a light fixture mounted on a side of a building or several hundred feet in the air has to be repaired or relamped.
Thus, the prior art does not teach or suggest a light fixture that uses a quick release, easy to use, latching mechanism that makes relamping the fixture simple.
It is therefore an object of the present invention to provide a light fixture with a latching mechanism that makes relamping the light fixture simple.
It is another object of the present invention to provide a light fixture with an easy-to-remove lens for accessing the internal mechanisms of the light fixture.
It is still another object of the present invention to provide a light fixture that produces a simple water resistant or watertight seal between a lens and the fixture""s housing.
It is yet another object of the present invention to provide a light fixture that includes a latching mechanism that remains connected to the housing after being released.
According to one aspect of the present invention, the light fixture includes a lens having two side edges including depending legs whose bottom surfaces are formed to mate with gaskets in corresponding grooves in the housing. Latch members are rotatably mounted on the housing along the two main side edges of the light fixture to clamp the lens in place against the gaskets along substantially their entire lengths. The latch members have first and second angularly related legs, the first of which includes a generally cylindrical rib. A recess is formed on an inner surface of the latch member adjacent the junction between the two legs. The bottom portions of the legs of the lens fit in the longitudinal grooves and compress the gaskets therein when the latch is closed. The cylindrical rib of the latch is received in a first longitudinal groove in the housing to rotate freely therein. When the latch is closed, the second leg of the latch rotates upward, so that it overlies the lens. In that position, the recess of the latch engages a mating edge of the lens in an over-the-center type action, which applies a clamping face to the lens along the entire length of the lens.